1. Field of the Invention
The subject of the present invention is a process for the combustion of a fuel in a burner of the type comprising an injector, which injector includes at least an inner first oxidizer feed passage, an intermediate fuel feed passage externally surrounding the first oxidizer feed passage, and an outer second oxidizer feed passage externally surrounding the fuel feed passage.
2. Description of the Related Art
The invention applies in particular to the supply of heat in processes for the production of materials.
Many processes for the production of materials, such as glass and ferrous or non-ferrous metals, involve heating steps in which burners of the aforementioned type are used with, for example, methane as the fuel and oxygen as the oxidizer.
The flames produced by these burners must comply with certain constraints.
For example, in the glass production processes, molten glass is generally transferred between two successive steps of the process by means of feeders. In such a feeder, the glass lying near the walls of the feeder tends to cool much more rapidly than the glass further away from these walls. Consequently, it is desirable to be able to reheat the periphery of the glass without reheating the core of the latter, in order to maintain an approximately homogeneous temperature profile in the sections of the molten material.
For this purpose, burners of the aforementioned type are placed in the walls of these transfer feeders. Unfortunately, the known combustion processes using burners of the aforementioned type do not always make it possible to adjust the length of the flames produced in order to satisfactorily heat the sections of the molten material fed.
Such is the case for the process described by document EP-A-763,692, in which the velocities of the fuel and of the internal oxygen exiting the injector are relatively high.
Similarly, the known combustion processes do not make it possible to comply with the constraints relating to the concentrations of the oxidizing species CO and O.sub.2, these being related to the length of the flame, at the exit of the burners placed near the baths of molten materials in metal production processes.
The object of the invention is to solve these problems by providing a combustion process for a burner of the aforementioned type, making it possible for the length of the flame and the concentrations of chemical species in it, especially CO and O.sub.2, to be finely adjusted.